1. Field of the Invention
The present invention relates generally to disease management systems and methods. The present invention also relates generally to disease simulation systems and methods, and in particular to a device and methods for simulating a disease control parameter and for predicting the effect of patient self-care actions on the disease control parameter.
This invention further relates to a device for advising a patient of the consequences of life-style and adherence to a medical regimen on disease control parameters. The present invention further relates generally to an electronic or virtual pet device. More particularly, the invention relates to a virtual pet device which simulates patient disease control parameters in response to a virtual medical regimen imposed for the treatment of a chronic disease or disorder.
2. Background of the Related Art
Managing a chronic disease or ongoing health condition requires the monitoring and controlling of a physical or mental parameter of the disease Exams of these disease control parameters include blood glu diabetes, respiratory flow in asthma, blood pressure in hypertension, cholesterol in cardiovascular disease, weight in eating disorders, T-cell or viral count in HIV, lung function or body weight in cystic fibrosis, and frequency or timing of episodes in mental health disorders. Because of the continuous nature of these diseases, their corresponding control parameters must be monitored and controlled on a regular basis by the patients themselves outside of a medical clinic.
Typically, the patients monitor and control these parameters in clinician assisted self-care or outpatient treatment programs. In these treatment programs, patients are responsible for performing self-care actions which impact the control parameter. Patients are also responsible for measuring the control parameter to determine the success of the self-care actions and the need for further adjustments. The successful implementation of such a treatment program requires a high degree of motivation, training, and understanding on the part of the patients to select and perform the appropriate self-care actions.
One method of training patients involves demonstrating the effect of various self-care actions on the disease control parameter through computerized simulations. Several computer simulation programs have been developed specifically for diabetes patients. Examples of such simulation programs include BG Pilot.TM. commercially available from Raya Systems, Inc. of 2570 El Camino Real, Suite 520, Mountain View, Calif. 94040 and AIDA freely available on the World Wide Web at the Diabetes UK web site.
Both BG Pilot.TM. and AIDA use mathematical compartmental models of metabolism to attempt to mimic various processes of a patient's physiology. For example, insulin absorption through a patient's fatty tissue into the patient's blood is represented as a flow through several compartments with each compartment having a different flow constant. Food absorption from mouth to stomach and gut is modeled in a similar manner. Each mathematical compartmental model uses partial differential equations and calculus to simulate a physiological process.
This compartmental modeling approach to disease simulation has several disadvantages. First, understanding the compartmental models requires advanced mathematical knowledge of partial differential equations and calculus which is far beyond the comprehension level of a typical patient. Consequently, each model is an unfathomable "black box" to the patient who must nevertheless trust the model and rely upon it to learn critical health issues.
A second disadvantage of the compartmental modeling approach is that a new model is needed for each new disease to be simulated. Many diseases involve physiological processes for which accurate models have not been developed. Consequently, the mathematical modeling approach used in BG Pilot.TM. and AIDA is not sufficiently general to extend simulations to diseases other than diabetes.
A further disadvantage of the modeling approach used in BG Pilot.TM. and AIDA is that the mathematical models are not easily customized to an individual patient. As a result, BG Pilot.TM. and AIDA are limited to simulating the effect of changes in insulin and diet on the blood glucose profile of a typical patient. Neither of these simulation programs may be customized to predict the effect of changes in insulin and diet on the blood glucose profile of an individual patient.
Cystic Fibrosis
Cystic fibrosis (CF) is a hereditary disease or genetic disorder caused by a single gene. About 1 in 20 persons carries a gene for the disorder. A key feature of cystic fibrosis is the production in the bronchial tubes of viscous mucus which is difficult to expectorate and which therefore tends to accumulate in the bronchial tubes. The mucus provides a breeding ground for microorganisms, which may lead to respiratory infections, including pneumonia. Untreated, a child with cystic fibrosis is likely to experience recurrent respiratory infections. Repeated bouts of pneumonia in children with cystic fibrosis usually lead to bronchiecstasis, a condition which makes the lungs even more susceptible to further bouts of pneumonia.
Treatment with various medications, including antibiotics, is enabling more cystic fibrosis patients to survive into early adulthood. In addition, in order to keep the lungs as free of mucus as possible, respiratory physical therapy, including postural drainage, may be called for.
Recently, treatment with Pulmozyme.TM. has been introduced as a means of reducing the severity of one of the major symptoms of the disorder, i.e. the accumulation of thick mucus. Pulmozyme.TM. contains an enzyme which breaks down DNA in the mucus, thereby decreasing the viscosity of the mucus and facilitating expectoration of the mucus.
Another feature of cystic fibrosis is a deficiency in digestive enzyme production from the pancreas. Consequently, in an untreated child, ingested food retains its fat components and is only minimally digested, leading to malabsorption. As a result the child gains little weight, and at the same time the stools are large, pale, and greasy. This condition may be treated by taking pancreatic enzymes. At the same time it is advisable to decrease the amount of fat in the child's diet.
In summary, cystic fibrosis is a debilitating condition which affects many children in the U.S. and elsewhere. Due to the chronic nature of the condition and its symptoms, cystic fibrosis represents a major burden to the child and the child's family.
In order to increase a child's chances of survival to adulthood, strict adherence to a complex, multicomponent medical regimen is indicated. A medical regimen for a child afflicted with cystic fibrosis typically includes daily administration of medications, including Pulmozyme.TM. and oral antibiotics, as well as pancreatic enzymes, vitamin supplements, and chest physical therapy. Such a medical regimen is described more fully hereinbelow with reference to the virtual pet device of the present invention.
Due to the on-going, long-term nature of the cystic fibrosis disorder and the medical treatment indicated for it, a child (and possibly the child's family) may tend to lose interest in the medical regimen. This is especially true when little or no long-term improvement in the patient's condition is attained. This situation can lead to discouragement and a lack of interest in medical treatment. Any device or method which can serve to educate or involve the child in his/her medical treatment, or which can directly motivate the child to greater adherence to the indicated medical regimen is of great benefit. This is so because failure to adhere to a recommended medical regimen usually signals a death knell for the cystic fibrosis patient.
Electronic, hand-held, interactive virtual pets are extremely popular with children, especially with those in the 5-12 years old range. Some current examples of these devices are Giga-pet (manufactured by Tiger Electronics, Ltd., Vernon Hills, Ill.), Nano Pet (Playmates Toys, Inc., Costa Mesa, Calif.), and Tamagotchi (Bandai America, Inc., Cypress, Calif.) etc. In many cases, a child's virtual pet is his/her more or less constant companion. For example, the pet may be the first object picked up by the child upon waking in the morning, may accompany the child to school during the day, and be the last item to be interacted with by the child at bedtime. Due to the high level of compatibility between a child and this type of device, and the amount of time spent "together", an appropriately designed pet has the potential for a substantial impact on the child's routine, state of mind, and well-being. For example, a virtual pet with a certain set of characteristics or needs can convey those characteristics or needs to a child in a way that formal training or interaction with less "compatible" devices would fail to achieve.
The present invention relates to an electronic virtual pet device, wherein the virtual pet is afflicted with a chronic disease or disorder. An appropriate or standardized medical regimen for the pet may be programmed into a microprocessor of the device, together with appropriate disease control parameters (e.g. lung function, body weight) for the pet. The child (pet owner) is responsible for entering into the pet information concerning the virtual treatment administered to/received by the pet. Based on such data, the virtual pet device can calculate disease parameter values to be displayed to the child or other owner of the device. If the pet receives appropriate and timely medical treatment according to a recommended or ideal virtual medical regimen, the pet's health will allow him to lead a productive life and to survive into adulthood. On the other hand, if the virtual medical regimen of the pet is inappropriate, the health of the virtual pet will suffer accordingly, and it may die prematurely.
It is worth noting that studies on the involvement of children with their own health care have shown increased compliance to their treatment regimen, increased patient satisfaction with treatment, increased feeling of control, increased sense of competence and independence, and most importantly, improved health, reduced clinical utilization, and reduced health care costs.